A substrate polishing apparatus that polishes a substrate such as a semiconductor wafer polishes a substrate held by a top ring by pressing the substrate to a polishing table. To transfer the substrate from a transport mechanism to the top ring, the substrate supported by the transport mechanism is firstly caused to come into contact with a membrane that is provided on a lower surface of the top ring and concentrically divided into a plurality of areas. Then, the substrate is vacuum drawn from a hole formed in the membrane, so that the substrate is adsorbed to the membrane.
It is desired to provide a substrate adsorption method, a substrate holding apparatus, a substrate polishing apparatus, an elastic film, a substrate adsorption determination method for a substrate holding apparatus, and a pressure control method for a substrate holding apparatus, for appropriately handling a substrate.
According to one embodiment, a method to adsorb a substrate to a top ring comprising a top ring body and an elastic film under the top ring body, the method comprises: vacuuming at least one area among a plurality of areas formed concentrically between a top face of the elastic film and the top ring body under a state where a bottom face of the substrate is supported by a support member and atop face of the substrate contacts a bottom face of the elastic film; measuring a flow volume of gas in an area located outside one or more areas to be vacuumed; determining whether the substrate is adsorbed to the top ring based on the flow volume of the gas; and after it is determined that the substrate is adsorbed to the top ring, separating the elastic film to which the substrate is adsorbed from the support member.
According to another embodiment, a substrate holding apparatus comprises: a top ring body; an elastic film under the top ring body, a plurality of areas being concentrically formed between a top face of the elastic film and the top ring body; a pressure controller configured to vacuum at least one area among the plurality of areas under a state where a top face of a substrate whose bottom face is supported by a support member contacts a bottom face of the elastic film; a flow meter configured to measure a flow volume of gas in an area located outside one or more areas to be vacuumed; and a determiner configured to determine whether the substrate is adsorbed to the top ring based on the flow volume of the gas.
According to another embodiment, a substrate holding apparatus comprising: a top ring body; an elastic film comprising a first face and a second face opposite the first face, a plurality of areas being formed between the first face and the top ring body, the second face being capable of holding a substrate; a first line communicating with a first area among the plurality of areas and capable of pressuring the first area; a second line communicating with the first area and capable of exhausting the first area; a measurement instrument whose measurement value varies based on a flow volume of the first area; a third line communicating with a second area among the plurality of areas and different from the first area, the third line being capable of pressuring or depressurizing the second area.
According to another embodiment, a substrate adsorption determination method for a substrate holding apparatus, the method comprising: depressurizing a second area formed between a top ring body and a first face of an elastic film in the substrate holding apparatus, pressuring a first area formed between the top ring body and the first face of the elastic film different from the second area and making a fluid through a second line communicating with the first area; and determining whether the substrate is adsorbed to a second face of the elastic film opposite the first face based on a measurement value varying according to a flow volume of the first area.
According to another embodiment, a pressure control method for a substrate holding apparatus, the method comprising: pressurizing a first area formed between a top ring body and a first face of an elastic film in the substrate holding apparatus, and making a fluid through a second line communicating with the first area; and controlling a second area formed between the top ring body and the first face of the elastic film different from the first area based on a measurement value varying according to a flow volume of the first area.
According to another embodiment, an elastic film used with a top ring body provided with a first hole at an outside of a first portion and a second hole at an inside of the first portion to configure a substrate holding apparatus, the elastic film comprising: a first face provided with a second portion capable of being engaged with the first portion, a plurality of areas being formed between the first face and the top ring body; and a second face opposite the first face, the second face being capable of holding a substrate.
According to another embodiment, a substrate holding apparatus comprising: a top ring body provided with a first hole at an outside of a first portion and a second hole at an inside of the first portion; an elastic film comprising: a first face provided with a second portion capable of being engaged with the first portion, a plurality of areas being formed between the first face and the top ring body; and a second face opposite the first face, the second face being capable of holding a substrate; a first line being capable of pressuring a first area through the first hole positioned at the first area among the plurality of areas; a second line capable of depressurizing the first are through the second hole positioned at the first area; a measurement instrument whose measurement value varies based on a flow volume of the first area; and a third line communicating with a second area among the plurality of areas and different from the first area, the third line being capable of pressuring or depressurizing the second area.